Which of these was the name of a popular British TV series?

"The Duchess of Duke Street" was a costume drama aired, originally, on the BBC from 1976-1977, though frequently repeated. It was created by John Hawkesworth (1920-2003) who was also responsible for the iconic series "Upstairs, Downstairs", broadcast on commercial TV.

Although presented as fiction, there is certainly a biographical element to the series. The central character, Louisa Leyton Trotter (portrayed in the series by Gemma Jones) is loosely based on the real-life Rosa Lewis (1867-1952) who ran the Cavendish Hotel and was, in fact, nicknamed "The Duchess of Jermyn Street".

Both women experienced a rags to riches existence. In the TV version, Louisa is a humble cook working in a wealthy household, but fate takes a hand when she is unexpectedly called on to prepare dinner for a visit from the Prince of Wales, later King Edward VII (who also features in "Upstairs, Downstairs"). She has an affair with him, and later marries Gus Trotter, a butler, in a marriage of convenience. They purchase the rundown Bentinck Hotel, but are quickly overwhelmed by debt, and Louisa's health suffers. The rakish but sympathetic Charlie Tyrell takes pity on her, and the two become partners, and later lovers, though Charlie dies in the trenches in World War I before they can fulfil their plans to marry.

The series ends on a poignant but not unhappy note, with Louisa's daughter Lottie finally taking up a singing career with her mother's blessing.